In a digital television system having a picture-in-picture (PIP or pix-in-pix) feature, two images from possibly unrelated sources are displayed simultaneously on the TV screen as a single composite image. The composite image includes a small picture (defined by an auxiliary video signal, for example, from a VCR) displayed as an inset within a large main picture (defined by a primary video signal, for example, from the TV antenna). U.S. Pat. No. 4,638,360 issued to Christopher, et al., and entitled "TIMING CORRECTION FOR A PICTURE-IN-PICTURE TELEVISION SYSTEM", describes an illustrative PIP system.
It is desirable to identify the channel (e.g., stereo transmission, channel number, TV station code, network identification code, etc.) for the small inset picture. Labeling of the small inset picture is especially important when a number of small inset pictures (e.g., 16) from different channels are simultaneously displayed on the television screen, for example, in the multiple pix-in-pix or TV guide mode.